Alloy



Patented Dec. 23, 1941 ICE ALLOY Reginald S. Dean and Clarence T. Anderson, Salt Lake City, Utah, assignors to Chicago Development Company, Chicago, 11]., a corporation of Illinois No Drawing. Application March 24, 1941, Serial No. 384,804

4 Claims. (Cl. 148-32) forms for use as structural elements. We have also disclosed that such alloys when properly heat-treated possess high vibration damping The heat treatment capacity at low stresses. disclosed in our aforementioned application comprises quenching the alloys from temperatures of approximately 900 degrees C. and reheating them to temperatures irom approximately 400 degrees C. to approximately 600 degrees C.

In accordance with our present invention, we v have discovered that exceptionally high vibration damping capacities can be developed in manganese-nickel alloys, the manganese content of which varies irom 82.5% to 95%, balance nickel. In general, such results are brought about by heating said alloys to a temperature between about 900 degrees C. and their meltingpoint and slowly cooling the same. By so proceeding, vibration damping capacities of from agg-oximately 10% to 13.5%have' been devel- I In an illustrative example, an'alloy containing 85% electrolytic manganese, having a purity of 99.9%, balance electrolytic nickel, was heated to 900 degrees C. and then slowly cooled to room temperature in an ordinary heat-treating furnace, the time required to efiec't the cooling being approximately eight hours. The resulting alloy .had a tensile strength of approximately 80,000 pounds per square inch, a yield point of 40,000

pounds per square inch, an elongation of 30% in two inches a'nda modulus of elasticity of 9.5x dynes per square centimeter.

Other highly satisfactory alloys within the percentake ranges set-out containing 84% manganese, balance nckel; 87.5% manganese, balance nickel; 90% man ganese, balance nickel; and 92.5% manganese, balance nickel. Since exceptionally highdamping ereinabove are those capacity is imparted to the alloy containing cooling, as used herein, we mean the cooling of the alloy at a rate which would be obtained if it were allowed to cool in an ordinary heattreating furnace. In general, the cooling rate should be such that at least six hours is required for the .alloy to reach room temperature after the heat is turned off. It will be understood, of course, that the length of time required to bring the temperature of the heated alloy down to room temperature during the slow cooling process the alloy element being treated as' well as upon the exact results desired by way of vibration damping capacity and other properties. It will be understood also that the slow cooling may be carried out in air although, for best results, it should becarrled out in an inert atmosphere.

'The alloys of our present invention may be employed for various purposes .wherein high vibration damping capacities at low stresses are desired. Illustrative uses include the manufacture of gears and springs for the automotive, railroad and other industries, machine elements in general, sheet and foil for use as acoustic insulators and the like, water pipe and other pipe sections, railroad track sections, ship and submarine armour and the like. i

What we claim as new and desire protect by Letters Patent of the United 812W 1. An alloy of manganese and nickel contain- .ing from 82.5% to 95% manganese, balance nickel, said alloy having a vibration damping capacity of more than 5% at low stresses and resulting from heating said alloy to a. temperature between about 900'degrees C. and its melting point and slowly cooling the same to room temperature.

. 2. An alloy consisting of about manganese and about 15% nickel, said alloy having a high vibration damping capacity at low stresses and resulting from heating said alloy-to a temperature between 900 degrees C.- and its melting point and slowly cooling to room temperature. 7

85% manganese, balance nickel, it will be understood, it will be understood that we regard said alloy "as representing a particularly preferred embodiment of our present invention. It will be understood that by' the term "slow ing to room temperature.

3. An alloy consisting of from 82.5% to electrolytic manganese having apurity of at least 99.9%, balance electrolytic nickel, said alloy having a high vibration damping capacity result- 4 ing from a heating to a temperature between 900 degrees C. and its melting point and slowly cool- 1 4. An alloy consisting'ot; about 85%. electrolytic manganese having a purity of at least 99.9%. balance electrolytic nickel, said alloy having a high vibration damping capacity at low stresses and resulting from heating said alloy to a temperature between 900 degrees C. and its melting point and slowly cooling to room temliterature.

REGINALD S. DEAN.

CLARENCE 'r. ANDERSON.

4 2,267,300- UNlTED'STATES PATENT oar S will depend, in part, upon the size and shape of r 

